Electric signaling system



F. N. REEVES.

ELECTRIC SGNALING SYSTEM.

APPLlcATmN man Nov. 3, 1917. Patented Apr. 20, 1920.

` 3 SHEETS-SHEET 1.

F. N. REEVES.

ELECTRIC SIGNALING SYSTEM.

APPLICATION FILED NOV. 3. 1917.

Patented Apr. 20, 1920.

3 SHEETS-SHEET Z.

NN Q Affy.

F. N. REEVES.

ELECTRIC SIGNALING SYSTEM.

APPLICATION FILED NOV. 3| ISI?.

Patented Apr. 20, 1920.

3 SHEETS-SHEET 3.

UNTTED sTATEs PATENT orrioE.

FRANK N. REEVES, OF NEWARK, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

ELECTRC SIGNALING SYSTEM.

Continuation of application Serial No. 127,659, lled October, 1918.

Specification of Letters Patent.

Patented. Apr. 20, 1920.

This application filed November 3,

1917. Serial No. 200,058.

To all whom t may Concern:

Be it known that I, FRANK N. REEVES, a citizen or the United States, residing at N ewarlr, in the county oi Essex and State of New Jersey, have invented certain new and usei'ul Improvements in Electric Signaling Systems, ci which the following is a iull, clear, concise, and exact description.

r1`his invention relates to electric signaling systems, and more particularly to a signaling system employed in automatic telephone exchanges. rlhis application is a continuation of my application Serial No. 127,659, iiled October 25, 1916.

1t is the object of the. present invention to provide a new and improved signaling arrangement in which the amount of apparatus needed for transmitting signals between two points, such as two operators positions, is reduced to a minimum.

According to' the main feature of the present invention, a group of variably operable signals, such as lamps provided at one point, may be selectively associated with a controlling station.

in the drawings Figure 1 represents as much of a controlling operators position as necessary for a clear understanding of the invention; Fig. 2, to be placed above Fig.V 1, represents the arrangement of a trunk iinding switch by means of which the operators controlling circuit may be eX- tended to indicator switches arranged to actuatc the signals; Fig. 3, to be placed above Fig. 2, represents a plurality of variably operable number indicator. switches of the sequence switch type, adapted to be set under the control of the operator, and signals controlled by these switches.

El. sequence switch 100 shown in Fig. 1, Controls contacts 101, 102, 103, 104:, 105, 106 and 107. These contacts are closed onlyin such 'positions of the sequence switch as are indicated adjacent the respective contacts. A master contact 108 of the sequence switch is closed in all positions, except the positions indicated adjacent thereto. This sequence switch and the other sequence switches used in the present system,

may be ot the same structure as-described in Patent No. 1,127,808 to J. N. Reynolds and C. F. Baldwin issued Feb. 9, 1915.

A sender shown within the dotted rectangle in Fig. 1, is arranged in accordance with the sender fully described in Patent No. 1,168,319 to A. E. Lundell issued Jan. 18, 1916. Contacts 109 and 110 are controlled by a sequence switch (not shown) associated with this sender. A relay contact 111 is opened under the control of the socalled upper zero counting relay. The number of operations to be performed by the counting relays until the energization of the upper Zero counting relay occurs, is predetermined by the adjustment oi the sender; and the successive actuation of the predetermined number of counting relavs is controlled by a stepping relay 112. u

The sequence switch contacts shown in the lower leiht-hand part ci Fig. 1 are partlv controlled by a sequence switch 100 and sender sequence switch. All the other sequence switch contacts shown in Fig. 1 are controlled by a sequence switch 113. The sequence switches 113 and 100, by means of their contacts, control the operation of a selector switch 116. The sequence switch 100, and another sequence switch (corresponding to 113) control the operation or' a selector switch 116. In view of the fact that the operation oi sequence switches 100 and 113 and selector 116 is similar to the operation ciE sequence switch 100 and the sequence switch corresponding to 113. only that of sequence switches 113 and 100 and selector 116 wiil be described in detail. lt will be obvious from a study ot the above Patent No. 1,168,319, that either one of the senders shown in Fig. 1 may be associated with'either one oi the selector switches.

An allotter 200 (Fig. is of the same structure as the sequence switches used in this system and Controls the contacts shown within the dotted rectangle around such allotter. Under the control of the allotter 200. trunk iinder 201 is preselected for service. The trunk finder may be of the same structure as the cord finder fully described in patent No. 1,168,319 to Lundell, Jan. 18. 1916, or the switch structure disclosed in patent No. 1,123,696 to Craft and Reynolds. Jan. 5, 1915. rEhe allot-ter 200 preselects the trunk finder 201 by moving a sequence switch 203, associated with such trunk finder, out of position 18 and into position 1. The allotter has no normal position and will accomplish this preselecting operation when in position 1. When the allotter is in position 4, into which position it is moved aiter the trunk finder associated with sequence switch 203 'has been taken into use, it will preselect for use a trunk finder associated with sequence switch 203, it such sequence switch was standing in position 18; that is to say, was awaiting preselection. r)The operation of sequence switches 203 and 203 and of the trunk iinders associated with such sequence switches is identical, and for this reason, only the operation of sequence switch 203 and trunk finder 201 is disclosed in detail herein. Only so much is shown oi the circuits of sequence switch 203 as is necessary for a full understanding ot the present invention. The trunk iinder 201 and the trunk inder associated with the sequence switch 203 may seize, under the control of their associated sequence switches, any one of a plurality of trunks seized by selector 116 or selector 116. The drawings show only means for permitting trunk iinder 201 to select and seize a trunk seized by selector 11, as it is believed to be obvious how trunk finder 201 may be caused to select another trunk selected by selector 116, or any one of a plurality of trunks seized by selector 116, or how the trunk finder associated with sequence switch. 203 may be caused to seize any one of the trunks selectable by trunk finder 201.

An allotter 202 of the same type as the sequence switches used in this system, controls the contacts shown within the dotted rectangle around this allotter.

In addition to the above mentioned function of sequence switch 203, this sequence switch controls also theoperation of indicators 301, 302, 303, 304 and 305 (Fig. 3). These indicators may be set in response to the adjustment of the sender, in accordance with the numerical designation of a called line. The indicators are permanently associated with the trunk iinder 201, and are thus connected to the sender. Each indicator controls the contacts shown above and below its power magnet with certain exceptions to be noted later. The contact shown directly above each power magnet is the vmaster contact controlling the stoioino of the respective indicators in the positions noted adjacent such contacts.

Each of the indicators 300, 302, 303 and 304 may control, by means of its contacts, the variable operation of a set ot lamps like 348. Depending upon the setting of the indicators, a certain number of lamps are lighted to display any one of the numerals 0 to 9 (both inclusive), and thus indicate the number of the called subscribers line to the operator who controls the completion of the desired connection. Such operator is usually known as a B operator.

In the same manner as sequence switch 203, sequence switch 203 controls theoperation of a set of indicators similar to those shown in Fig. 3. The circuits and mecha nisrns of such indicators are not disclosed, because it would involve only a repetition of the matter shown in Fig. 3 and .of the detailed description of this showing. lithin a dotted rectangle in the upper lett-hand part of Fig. 3 there are shown contacts controllableby indicators similar to 300 and 301, which are in turn controlled by the sequence switchv 203.` Y

Each set of lamps 348 is provided in cominon to the corresponding indicators controlled by sequence switches 203 and 203, and mayl obviously be made common to more than two corresponding indicators.

lt will be seen Jfrom the above that both sets of indicators A(those associated with sequence switch 203 and those associated with sequence switch 203) may be simultaneously controlled to actuate the lamps 34S to display a numeral. This may result in the. sending of a false signal to the B operator, and, for this reason, means are provided in the form of the allotter 202 for determiningthe succession in which the operation ofthe indicators should become eiiective. As will be apparent from the detailed description of the operation of the system, when allotter 202 is in position 1, the indicators associated with sequence switch 203 are permitted to cause the lighting of the lamps 348, and when this allotter is in position 4, the indicators associated with sequence switch 203 will be permitted to perA formV this function. Means are also provided for preventing the allotter 202 from moving out of position 1 and into position -L-l until the indicators associated with sequence switch 203 have successfully completed their operation. Y

'The invention will be more readilyunderstood from the following detailed descrip tion of a telephone system, in which a connecting or A operator conveys a visual signal to a B operator, and the appended claims As soon as a connecting operator receives a call-through a trunk 114, and ascertains the `number of the subscriber wanted, she depresses an assignment key 115, closing a circuit from the plus pole oi' battery through the Contact of this key, the contact 102 and the power magnet of sequence switch 100, to the minuspole of battery. Under-the control of its master contact 108, the sequenceswitch is moved into position 11. The operator then adjusts the sender which has been connected tothe trunk 114 in a manner described in the .mentioned Patent No. 1,168,319, for controlling the setting'ot1 a selector 116 onto a trunk leading to the otlice to which the called subscriber is connected,

and the setting of the indicators in accordance with the number of the called subscriber. lWhile the sequence switch 100 is moving from position 1 into position 11, the selector switch 116 is operated. Patent No. 1,168,319 contains a complete disclosure of the operation of selector switches such as 116, and for this reason no attempt will bc made in the present description to further dwell on the operation of this selector. lt will be assumed that the selector has been successfully set onto the desired terminals, such as 117, 118. A fundamental circuit is closed thereupon from the plus pole of battery, through a sequence switch contact 119, a resistance 120, terminal 118, selector wiper 121, sequence switch contact 104, sender sequence switch contact 109, the relay contact 111, the winding of relay 112, sequence switch contact 105, wiper 137, terminal 117, conductor 156, resistance 121", sequence switch contact 122, the winding of a relay 123, and sequence switch contact 1251., to the minus pole of battery. Relays 112 and 123 become energized. Relay 123 closes a circuit from the plus pole of battery through its right-hand armature and front contact, a contact 125 and the power magnet of sequence switch 113, to the minus pole of battery. Under the control of its master contact 126, the sequence switch is moved into position 2. A circuit is now closed from the plus pole of battery through sequence switch contact 127, conductor 128, sequence switch `contacts 204, 205, a conductor 206 and the winding of a relay 207 to the minus pole of battery. Relay 207 becomes energized and closes a circuit from the plus pole of bat tery, through its right-hand armature and front contact, conductor 208, a contact 209 and the power magnet ot sequence switch 203 to the minus pole of battery. Under the control of its master Contact 210, the sequence switch is moved out ot position 1 into position 2. The positions in which Contact 210 is open are indicated adjacent to a master contact 210 of sequence switch 203. lWhen sequence switch 203 passes through position 1%, the above traced circuit or relay 207 is replaced by a circuit extending from the minus pole of battery, through the winding of this relay, conductor 206, sequence switch contacts 205 and 219, and the back contact and armature ot relay 218 to the plus pole of battery.

ln position 2. of the sequence switch 203, a magnet 211 becomes energized by a circuit extending from the minus pole of battery, through the winding of this magnet, a sequence switch contact 212, a conductor 208 and the right-hand front contact and armature 207 to the plus pole or battery. Under the control of magnet 211, the wipers of the trunk iinder switch 201 are caused to move in an upward direction over a bank ot terminals containing` one set of contacts for each trunk to which the selector 116 has access. rlhe terminals shown in Fig. 2 are individual to the trunk terminating in selector contacts 117 and 118. Upon the engagement of this set ot terminals; that is to say, upon the engagement of a set of terminals individual to a trunk, the sequence switch 113 associated with which is in position 2, a circuit is closed from the plus pole or' battery, through sequence switch contact 129, conductor 130, terminal 291, wiper 292, conductor 293, sequence switch contacts 213 and 214, conductor 215, sequence switch contacts 216 and 217, and the winding of a relay 218, to the minus pole of battery. Relay 218 by attracting its armature, closes a locking circuit for itself through sequence switch contacts 216 and 217, and by opening its back contact, opens the circuit of relay 207. In order to insure the proper centering of the trunk iinder wipers on the terminals selected, whenever these wipers rest below or above a certain terminal, a circuit is closed trom the plus pole ot battery, through a brush 220 moved in an upward direction, together with the wipers of the trunk iinder, a conducting segment 221 adapted to be engaged by this brush, conductor 222, sequence switch contact 223, conductor 224i, the left-hand armature, front contact and the winding of relay 207, to the minus pole of battery. As soon as the trunk nder wipers are exactly centered on the selected set of terminals. the brush 220 engages one of the insulated segments 225, and therefore, upon the energiaation of lay 218, relay 207 becomes denergized and closes a circuit from the plus pole oic battery through its right-hand armature and back contact, a contact 226 and the power magnet of sequence switch 203 to the minus pole ci battery, for moving this sequence switch out ot position 2 into position in position 3 of sequence switch 203, a circuit is closed from the plus pole of bat tery through the armature and front contact of relay 218, sequence switch contacts 216 and 227, conductor 228, wiper 29a, terminal 295, conductor 163, a contact 131 and the power magnet of sequence switch 113, to the minus pole of battery, for moving sequence switch 113 out oi2 position 2 and into position 3. Sequence switch contact 122 is now open, but relay 123 remains energized, a circuit being closed from the minus pole of battery, through sequence switch contact 12a, the winding ot relay 123, .cquence switch contact 1211, the lei:u

hand armature and front Contact oi relay 123, sequence switch contacts 135 and 136, and then through the above traced fundamental circuit. n position 3 of sequence switch 113, a circuit is closed for again energizing relay 207. This circuit may be traced from the minus pole of battery, through the winding of relay 207, sequence switch contacts 205 and'229, conductor 230, wiper 296, terminal 297, conductor 164, sequence switch contacts 132 and 133, and the right-hand iront contact and armature of relay 123V to the plus pole of battery. Upon the energization of relay 207, a circuit is closed from the plus pole of battery, through the right-hand armature and front contact of this relay, conductor 208, and sequence switch contacts 209 and 235, and the power magnet of sequence switch 203, to the minus pole of battery, for moving this sequence switch out of position 3 and into position 4.

Assuming that'the allotter 200 is in position 1, a circuit will now be closed from ground, through allotter Contact 236, sequence switch contacts 237 and 238, a contact 239 and the power magnet ol allotter 200, to grounded battery. Under the con# trol of its master contact 240 the allotter is moved out of position 1 into position 4, in which position it controls the preselection of a sequence switch 203', and thus a trunk finder similar to 201 with which such sequence switch is associated. If sequence switch 203' is standing in position 18, a circuit is closed from grounded battery, through the power magnet and contacts 235 and 237' of sequence switch 203', and contact 236 of allotter 200 to ground. Under the control of its master contactV 210', sequence switch 203' is moved into position 1, in which position relay 207 may be energized in the same manner as relay 207, for moving the sequence switch 203 out of position 1 and into position 2. rl`he circuit eX- tends from the minus pole of battery,

through the power magnet and contactsV 235', 209 of sequence switch 203', and the right-hand front-contact and armature of relay 207 to the plus pole of battery. In position 2 or sequence switch 203', the trunk finder served by the sequence switch is started to hunt :for the trunk assigned by the connecting operator. n

A circuit is now closed from the minus pole of battery, through sequence switch contact 124, the winding of relay 123, sequence switch contacts 134, 165 and 166, conductor 167, terminal 29S, wiper 299, conductor 299', sequence switch contact 298',

conductor 297', conductor 369, normally Closed Contacts 370, 371, 372, 373, 374, 375 and 376 of the indicators 300 to 305, respectively, conductor 245, wiper 296', terminal 295', conductor 141, sequence switch contacts 140 and 136, and through the fundamental circuit to the plusv pole of battery at sequence switch contact 119. Due to the closure of this circuit, if the relay 123 failed to lock up in the above described manner, it will now become energized and will close its locking circuit.

In position 4 of sequence switch 203, the number indicator 300 is operated. The circuit for this indicator extends from the minus pole` of battery through the power magnet of the number indicator 300, con-V ductor 306, sequence switch contact 241, conductor 224, the left-hand armature and front contact of relay 207, conductor 206, sequence switch contacts 205 and 229, conductor 230, wiper 296, terminal 297, conductor 164, sequence switch contacts 132 and 133 and the right-hand front contact and armature of relay 123 to the plus pole of battery. The indicator is moved under the control or its master Contact from position to position. While moving from one position to the next, that is to say, betweenV positions N and X, positions lX and 0, posi tions 0 and 1, etc., a contact 310 is closed. In response to each closure of contact 310, a shunt circuit is closed for relay 123, which circuit extends from the minus pole of battery through sequence switch contact 124, the winding of relay 123, sequence switch Contact v134, the left-hand armature and front contact of relay 123, sequence switch contacts 135 and 140, conductor 141, terminal 295', wiper 296', conductor 245, conductor 311, contact 310, conductor 313, sequence switch contact 246 Vand the right-hand front contact and armature of relay 207, to the plus pole of battery. Due to the closure of this shunt circuit through the winding of relay 123, the stepping relay 112 at the sender becomes denergized and starts the successive operation of the counting relays. After the indicator. 300 takes a number of steps predetermined by the setting of the sender, which fact is indicated to the sender by the number of. closures of contac't'310, the upper zero counting relay (not shown) becomes energized andopcns at Contact 111 the fundamental circuit. The counting relays will be unlocked because sequence switch contact 109 is opened and relay 112 becomes denergized. Relay 123 becomes also energized and causes relay 207 to release its armdtures.

As soon as the indicator 300 reachedposition X a circuit wasjclosed for the sequence switch 203 from the minus pole or" battery through the powermagnet of this sequence switch, sequence switch contact 247, conductor 24S, indicator Contact 314, the normally closed contacts 3154, 316, 317,

31S and 319 of the other indicators respec- Y lay 207 becomes denergized, through the back contact and right-hand armature of this relay to the plus pole of battery. The sequence switch 203 is thus moved into posit-ion 5 upon the opening of the fundamental circuit.

ln the meantime, the fundamental circuit is again closed, resulting in the energization of relays 112 and 123, and the latter causes the operation of relay 207. The circuit orn relay 123 may be traced as follows: minus pole o1n battery, 124, 123, 134, 165, 166, 167, 298, 299, 299', 294', 377, 378, 371, 372, 373, 37a, 37s, als, 29e', 295, iii, la 136 and then through the fundamental circuit to the plus pole of battery. rlhe plus battery at the right-hand armature of relay 123, which was connected through the lefthand armature and front contact of relay 207 to the power magnet of indicator 300 in position 4 ot sequence switch 203, is now connected through` conductor 224, sequence switch contact 250, conductor 251, and the power magnet of the indicator 301 to the minus pole of battery. This indicator begins to rotate now and controls in its contact 315 the operation of the stepping relay 112, and thus that of the counting relays. 1li/*hen the upper zer counting relay again becomes energized, relays 112 and 123 again become denergized, and the latter causes the dee'nergiaation of relay 207. 1V hen the relay 207 becomes deenergized, the sequence switch 203 is moved out oic position 5 and into position 6, the circuit extending from the plus pole of battery, through the right-hand armature and bach contact of relay 267, conductor 249, sequence switch contact 248', conductor 320, indicator contacts 319, 318, 317 and 316, indicator contact 321, conductor 322, a contact 251a and the power magnet of sequence switch 203 to the minus pole of battery. Upon the denergization of relay 207, the indicator 301 is arrested in the position predetermined by the sender. Upon the subsequent closure of the fundamental circuit, the energizing circuit of relay 123 is closed at sequence switch contact 298, and contact 379 of indilator 301. lWhen relay 207 becomes energized, indicator 302 is connected in circuit through conductor 323, sequence switch contact 252 and conductor 224. This indicator controls in its contact 324 the actuation of the sender stepping relay. After the setting of indicator 302 and upon the denergization of relay 123, the plus battery applied through the right-hand armature and contact of relay 207 to conductor 320 is eX- tended through indicator contact 325 and thence through the circuit traced in case oi indicator 300, including sequence switch contact 247, for moif'ing sequence switch 203 out oil position 6 and into position 7.

Upon the subsequent establishment of the fundamental circuit. the energizing circuit of relay 123 is completed at sequence switch contact 294 and contact 380 of indicator' 302, and thereupon the relay 207 connects plus battery through conductor 224, sequence switch contact 253, conductor 254, and the power magnet of indicator 303 to the minus pole of battery. This indicator controls at its contact 326 the actuation of the sender, and upon the denergization of relay 207, following the setting oia indicator 303, it will control at its contact 327 the closure oi a circuit traced in case of indicator 301 and including sequence switch contact 2515, for moving sequence switch 203 out of position 7 and into position 8,

Un the subsequent closure of the fundamental circuit, the energizing circuit of relay 123 is closed at sequence switch contact 298 and Contact 381 of indicator 303, whereupon the relay 207 connects plus battery through its left-hand armature, conductor 224 and contact 255, conductor 256, and the power magnet of indicator 304 to the minus pole of battery. lndicator 304 begins to operate and controls at its contact 328 the operation of the sender. lhen the upper zero counting relay again operates, the relays 112, 123 and 207 become denergized. The indicator 304 is arrested and closes a circuit at its contact 329 in the same manner as indicator 302, through sequence switch contact 247, for moving sequence switch 203 out of position 8 and into position 9.

In position 9 of the sequence switch, as soon as the fundamental circuit is again closed, the energizing circuit of relay 123 is closed at sequence switch contact 294', and a contact 382 of indicator 304, whereupon relay 207 applies plus battery through its left-hand armature, 'conductor 224, sequence switch contact 257, conductor 258 and the power magnet of indicator 305 to the minus pole off battery. Indicator 305, during its operation, controls at its contact 330 the operation of the stepping relay.

Upon the last opening ot the fundamental circuit by the upper zero counting relay, sender sequence switch contact 110 is closed, causing the movement of the sequence switch 100 out of position 11 and into position 16. Relays 112, 207 and 123 become deenergized.

After the setting of indicator 305 a circuit is closed from the plus pole of battery through the right-hand armature and back contact of relay 207, conductor 249, sequence switch contact 248', conductor 320, the con` tact 331 of the indicator 305, conductor 332, wiper 259, terminal 259, conductor 150, a contact 151 and the power magnet of sequence switch 113, to the minus pole of battery. This sequence switch is moved out of position 3 into position 4. A circuit is then closed from the minus pole of battery through sequence switch contacts 152 and 153, conductor 154, the winding of a relay 155, conductor 156, terminal 117, wiper 137, sequence switch contact 106. the secondary of a repeating coil 138, to the plus pole of battery. Belay 155 closes a circuit -from ground through sequence switch contact 157, the contact and armature ot relay 155, se-

quence switch contacts 158 and 159 and the winding of a relay 160 to the plus pole of battery. The relay 160 becomes energized and connects plus battery through its front contact and armature, conductor 163, terminal 295, wiper 294, conductor 228, sequence switch contacts 227 and 217, and the winding of relay 218 to the minus pole of battery. Relay 218 closes a circuit from the plus pole of battery through its armature and front contact, conductor 215, conductor 260, a contact 261 and the power magnet of sequence switch 203 to the minus pole of battery, for causing the movement ot this sequence switch out ot position 9 and into posi-tion 10. A circuit is now closed from the minus pole oi' battery, through sequence switch contact 262 and a lamp 263 to ground, lighting up this lamp. The lighting of this lamp indicates the successful setting of all the indicators.

A circuit is also closed from the minus pole of battery through the winding of relay 207, conductor 206, sequence switch contacts 264: and 227, conductor 228, wiper 294, terminal 295, conductor 163, and then through the right-hand armature and front contact of relay 160 to the plus pole of battery. Relay 207 closes a circuit from the plus pole of battery through its right-hand armature and contact, conductor 208, sequence switch contact 265, the armature and back contact of a relay 266 and the power magnet of allotter 202 to the minus pole of battery. Assuming that this allotter is now in a position other than position 1, such as position 17, it will rotate until it reaches position 1. In this position-the plus battery at relay I160 is connected, in the same manner as above described, to the conductor 206, and then through the left-hand armature and front contact or' relay 207, conductor 2211-, sequence switch Contact 266, conductor 267, a resistance 268, allotter contact 269 and the winding of the relay 266 to the minus pole of battery. Relay 266 becomes energized and opens in its back contact the driving circuit of allotter 202, thus causing the arresting of the allotter in position 1. .The plus battery at the right-hand armature of relay 207 is now connected through conductor 208, sequence switchcontact 265, the armature and 'front contact o't relay 266, allotter contact 270, a contact 271 and the power magnet of sequence switch 203 to the minus pole of battery, for moving. this sequence switch out of position 10 and into position 15. An allotter contact 272 is like a master contact and is closed in all positions eXcept in the positions indicated adjacent such contact. lVhile this contact is closed, relay 266 is short-circuited. For this reason it will be seen that the energization of 'relay 266, under the control of relay 207, is prevented, until the allotter 202 has isawisa actually reached its stopping position indicated by numbers adjacent to contact 272, and thus the allotter cannot be arrested ercept when exactly stationed in these positions.

In a similar manner the allotter 202 may be caused to move, under the control or" a relay similar to 207 individual to another trunk iinder 201, into such positions as indicated adjacent to contact 272, the stopping circuit of the allotter being then controlled in its contacts shown above and to the left-hand side of contact 260. T he allotter then, by closing the corresponding contact shown above contact 270, will cause the movement of the sequence switch, associated with said other trunk finder, out of position 10 and into position 15.,V

Supposing that the sequence 4switch 203 is standing in position 10 and relay 207 is energized. As soon as relay 266 becomes denergized, a circuit is closed from the plus pole of battery, through the right-hand armature and front contact of relay 207, contact 265 of sequence switch 203, the armature and back contact of relay 266, and the power magnet of allotter 202 to grounded battery. The closure of this circuit would cause the allotter to move out of position 1, and to rotate until relay 266 becomes energized. In the present case, the circuit of relay 266 is completed in position f1 of allotter 202. The circuit extends from the minus pole of battery, through the winding of rela-y 266, allotter Contact 260', resistance 268', conductor 267, Contact 266b of sequence switch 203', the left-hand armature and front contact of relay 207', conducttor 206, and then in the same manner as above described through the armature of relay 160, or the armature of a similar' relay associated with another trunk, to the plus pole ofbattery. In position a of allotter 202, a circuit would be closed from the minus pole of battery, through the power magnet and contact 271 of sequence switch 203, contact 270 of allotter 202, the front contact and armature of relay 266, contact 265 of sequence switch 203, and the righthand front contact and armature of relay 207 to the plus pole of battery. The sequence switch 203 would thus be moved into position 15. v

As it will be hereinafter set forth, in position 15 of a sequence switch like 203 or 203', the number of the called subscriber is displayed by means of lamp signals such as 348, in accordance with the set position of' the number indicators. The set of lamps 348 is common to a plurality of indicators like 300, and for this reason means are prodotted rectangle in F ig. 3. This means consists in the provision of a circuit extending from the minus pole of battery, through the winding of relay 266, contact 269 oit allotter 202 (which was moved into position 1 under the control of sequence switch 203), conductor 267, resistance 233, conductor 237, conductor 383, contact 334 of indicator 301, conductor 385, and contact 274 of sequence switch 203 to the plus pole ot' battery. Relay 266 is thus maintained energized while sequence switch 203 is in positions 14 to 17 (contact 274 being closed), and indicator 301 is in positions 0 to 4 (contact 384 being closed). Vhile relay 266 is energized, sequence switch 203 cannot cause the allotter 202 to move out of position 1 into position 4, and for this reason allotter 202 cannot cause the sequence switch 203 to move out of position 10 and into position 15. In position 15, sequence switch 203 causes the movement of an indicator similar to 301, controlling contacts 340 and 341, in the same manner as sequence switch 203 controls the movement of indicator 301 into position 4. An indicator similar to 300 controls contacts 353, 351, 354', 350, 352, 356, and 355 in the same manner as indicator 300 controls contacts 353, 351, 354, 350, 352, 356 and 355. In view et the fact that, by means of another trunk finder similar to 201, the indicator controlling contacts 353', 351', etc., may be associated with a trunk selected by another selector like 116, -this indicator may be operated siinultaneously with indicator 300 to light up a certain number oif the lamps of sets 348. Due to the provision of the above described arrangement whereby the sequence switch 203 is prevented from moving the indicator corresponding to 301 into position 4, this operation of the indicator corresponding to 300 is rendered temporarily ineifective.

The indicator 301 is used only for correcting the setting of indicators 300 and 302. This is necessary because the sender for controlling selector switches such as 116 used in this system, is arranged in accordance with a system of translation and may cause the sending of a different number of impulses than is represented by the numerical designation of the called subscribcr`s line. This arrangement of the indicators 300, 301 and 302 does not form a part of the present invention and will, therefore, not be fully explained herein. A description of such an arrangement and an explanation of its purpose may be found in a copcnding application of A. E. Lundell, Ferial No. 121.501, tiled September 1010. now Patent No. 1.260,412, Nlar. 26, 1913, and a patent to A. E. Lundell, No. 1,232,944, July 10, 1917. Attention is only called to the peculiar numbering of the master conductor 336, and sequence switch contact 273 to the plus pole of battery. Due to the closure of this circuit, the indicator 300 is caused to move into the next position, in

which the contact 333 is open, that is to say, e

if the indicator 300 has been causedL to nieve into an even-numbered position and the indicator 301 into position 2, the indicator 300 will be moved into the next highest oddnuinbered position.

1f the indicator 301 has been moved into position 1, and the indicator 302 into one of the positions noted adjacent to its contact 337, then, as soon asthe indicator 303 passes over position X, a circuit is closed roni grounded battery, through the power inagnet and contact 337 oi indicator 302, conductor 338, contact 330 of indicator 303, conductor 340% contact 3412L of indicator 301, conductor 336, sequence switch contact 27 to the plus pole of battery. Due to the closure of this circuit, the indicator 302 will be moved into a resting position next to the position in which it was standing.

1t the indicator 301 was moved into position 3, then beth its contacts 335 and 341LL are closed. For this reason. if the contact 333 of indicator 300 and the contact 337 of indicator 302 are closed, then the setting of both these indicators will be corrected.

After indicator 301 has corrected the setting of indicators 300 and 302, it is used for controlling the lighting of the lamps. As above described, upon the setting of the la st indicator 305, the sequence switch 203 moves under the control ot an allotter 202 into position 15. 1t will be remembered that only one sequence switch like 203 can he in position 15 at a time. As soon as the sequence switch 203 passes through position 14, a circuit is closed trom the plus pole et battery, through sequence switch contact 274, conductor 275, a contact 339 and the power magnet oit indicator 301 to the minus pole et battery. n the present system, the indicator 301 is moved only to some position between Zero and 3 for controllingthe incicators. Due to the closure of the above traced circuit, the indicator 301 is moved into position 4. 1n its fourth position this indicator closes the contacts shown above and below its contact springs 340. 341, 342. 343, 344, 345, 346 and 347. lt will be noted that contact springs 3410 and 341 are arranged to connect ground to contacts controlled by indicator 300; contact springs 342 and 343 to connect ground to contacts controlled by indicator 302; contacts 344 and 34:5, to connect ground to contacts controlled by indicator 303; and contacts 346 and 317, to connect ground to contacts controlled by indicator 3041. The contacts of indicator 300 are connected to a lamp set 348. v In the same manner, the above mentioned contacts of each of the other indicators are connected to a lamp set similar to 348. 'Ehe seven pairs of lamps of set 3&8 are permanently connected to the seven contacts of a plurality of indicators such as 300.

Due to the fact that the allotter 202 permits the movement of only one sequence switch like 203 out of position 10, into position 15, only one sequence switch like 203 can control the movement of its associated indicator 301 into position 4t. For this reason only one translator 301 can be in position 4 at a time.

It will be noted that the seven pairs of lamps are connected in numerical order to the seven contacts of indicator 300 to which ground has been connected by the indicator 301. The lamps are arranged in an elliptical form around the lamps numbered 4L. Supposing that the indicator 300 is standing in position zero, it will be seen that of its above mentioned seven contacts only contact 350, that is to say, the fourth contact, will be left open. For this reason all the lamps except the two lamps numbered t will be lighted. These lamps when lighted display the numeral Zero. If the indicator 300 is standing in position 1, then of the above mentioned seven contacts only 351 and 352 are closed. Thus only the #3 and #6 lamps are lighted and display the numeral 1.

In position 2 of indicator 300, the contacts 353, 354, 350, 352 and 355 are closed, causing the lighting of the lamps numbered 1, 2, 3, 4, 5 and 7. These lamps when lighted display the numeral 2.

In position 3 of the indicator 300, contacts 353, 351, 350, 352 and 355 are closed. The lamps numbered 1, 3, 4, Gand 7 will be lighted, causing the displaying of the numeral 3.

In position f1 of the indicator 300, contacts 351, 350, 352 and 356 are closed, causing the lighting of lamps numbered 2, 3, et and 6, causing the'displaying of the numeral 1.

In the other positions of indicator 300, the mentioned seven contacts will be closed in an order which may be readily ascertained from the drawings, and will cause the displaying oi a numeral corresponding to the resting position ot the indicator.

The other indicators, controlled by means of other contacts to which ground has been connected by indicator 301, cause the displaying o numerals in the same manner as described in connection with indicator 300.

The lamps controlled by springs 357, 358 and 359 of indicator 305, adjusted in accordance with the station designation of the desired party, are supplied with ground in position 15 of sequence switch 203, from sequence switch contacts 276 and conductors 360, and 361. The contacts of the indicator springs 357, 358 and 359 are wired to lamps adapted to display the letters It, (I, M and W. Y

In position 15 of sequence switch 203 a circuit is closed from grounded battery, through a resistance 218', sequence switch contacts 2111 and 213', and lamp 263 to ground. The lighting of this lamp, which has beenextinguished when the sequence switch' 203 moved out oi position 11, indicates the successful operation of the indicator.

The B operator, having learned the number of the called station, inserts plug P into the desired multiple ack J and signals the station in the well known manner. In response to the insertion of the plug into the jack a sleeve relay 123 becomes energized by current flowing through the sleeve contacts of the plug and jack, and closes a circuit through a sequence switch contact 125n for moving the sequence switch 113 out of position 4: and into position 6.

IVhen the sequence switch 113 opens its contacts 158 and 159, relay 160 becomes denergized and opens the above traced locking circuit of relay 207. This latter mentioned relay closes then a circuit from the plus pole oit battery, through its right-hand armature and back contact, the contact 226 and they powerv magnet of sequence switch 203 to the minus pole of battery, for Vdriving the sequence switch out of position 15 and into position 16. A circuit is now closed from the plus pole of battery, through the right-hand varmature and back contact of relay 207, conductor 24:9 and then this circuit divides into two branches, onel branch leading through sequence switch contact 277, conductor 278 and the power magnet of indicator 300, to the minus pole of battery, and the other branch through sequence switch contact 279, conductor 280 and the power magnet of indicator 301, to the minus pole of battery. Due to the closure of this circuit, the switches 300 :and 301 are returned to their normal position. The other indicators are returned to their normal positions by circuits extending from plus pole of battery, through sequence switch contact 281, conductor 360, a contact 361 and the power magnet of the indicator 302, to the minus pole of battery; from the plus pole of battery, through sequence switch contact 282, conductor 362, a contact 363 and the power magnet of indicator 303, to the minus pole or battery; from the plus pole of battery, through sequence switch contact 283, conductor 364, a contact 365 andthe power magnet ot indicator 304, to the minus pole or" battery; a circuit from the plus pole ot battery, through sequence switch contact 284, conductor 366, a contact 367 and the power magnet of the indicator 305, to the minus pole of battery.

lhen indicator 301 opens its contact 384, the relay 266 becomes denergized, and the equence switch 203 is permitted to control the operation of allotter 202. W'hen indicator 301 leaves position 4, the lamps are e2;- tin uished.

pon the denergization of relay 266, the sequence switch 203 is permittedL to operate in the above described manner. Ey causing the indicator corresponding to 301 to move into position 4, it will render eliective the setting of the indicator corresponding to 300 by lighting the lamps 348.

A circuit is also closed from the plus pole of battery, through the sequence switch contact 285 andthe winding of the magnet 286, to the minus pole of battery. Under the control of this magnet, the wipers of the trunk finder 201 and the brush 220 are caused to travel in a downward direction. As soon as brush 220 reaches its normal position, a circuit is closed from the plus pole of battery, through brush 220, a conducting plate 287, a contact 288 and the power magnet of sequence switch 203, to the minus pole of battery, for driving' this sequence switch contact out of position 16 and into position 17.

As soon as all the indicators are released normally a circuit is closed from the minus pole of battery, through the power magnet of sequence switch 203, sequence switch contact 289, conductor 290, the normally closed Contacts ses, sita, sie, 317, sie and :sie of the indicators, conductor 320, sequence switch contact 248, conductor 249, and the back contact of armature 207 to the plus pole of battery. Due to the closure of this circuit, the sequence switch 203 is moved out of position 17 and into position 18.

ln position`18 of the sequence switch 203, the Contact 204 is open, and therefore a sequence switch like 113 when it moves into position 2 and closes its contact 127 cannot cause the energization of relay 207 and thus operate the trunk i'inder 201 to associate'the indicators shown in F ig. 3 with the trunk seized by the selector 116. The sequence switch 203 will remain in position 18 until it is preselected for service by the allotter 200. rlhis will occur when in position 17 of the allotter, a sequence switch similar to 203 reaches position 4 and closes its contacts corresponding to contacts 237 and 238 ot sequence switch 203, for causing the movement ot the allotter out of position 17 into position 1. As soon as the allotter reaches position 1, a circuit is closed from ground, through its contact 236, the contact 237 and the power magnet of sequence switch 203 to grounded battery, for moving this sequence switch out of position 18 into position 1.

llhe apparatus shown in Figs. 2 and 3 is now again ready lor service.

The sequence switch 113 will be driven out of position 16 and back into its normal position, in response to the completion oi' the connection between the calling and called subscribers, in accordance with the iuimber displayed by the lamps, and in response to the restoration of this connection. The circuits or controlling such operation oi' the sequence switch are not disclosed in the present application, because they do not form part of the invention claimed hereinafter.

`What is claimed is:

1. ln combination, a plurality orn telephone lines, a plurality of senders, means for associating any one ot said senders with any one of said lines, a plurality of selectively operable switches arranged to operate under the control orn any one of said senders, a finder for each of said switches arranged to connect the associated switch to any one of said lines, means operative upon the connection of a sender to a line for operating one of said finders to connect with said last mentioned line, a variably operable signal, means controlled by any one of said switches for operating said signal, and means for permitting the successful operation of said signal by only one switch at a time.

2. In combination, a signal, a plurality ot switches, independent controlling devices for setting each of said switches into a certain position, a Contact for each ot said switches operable when the respective switch is in said certain position for actuating said signal, and means Jfor determining the succession in which said contacts should be actuated.

3. ln combination, an electric signal, two contacts, each arranged to actuate d nal, two controlling switches, one provided for each contact, and means for determining the succession in which the actuation or" said contacts should become effective.

4. In combination, an electric signal, two actuating circuits for said signal, two contacts in each of said circuits, means tor actuating one ot the contacts in both circuits, and means operative thereupon for determining the succession in which the second contacts should be actuated.

5. In combination, an electric sional, two actuating circuits for said signal, a pair of switching devices for controlling nach ot said circuits, means controllable at a distant point for operating one pair ot switching devices, other means controllable at a distant point for operating the other pair ot said devices, and a common means for coperat- .ing in the control of one switching device in each pair.

Y6. In combination, an electric signal, two actuating circuits therefor, a pair of switching devices for controlling each of said circuits, ineans controllable at a distant point for operating one pair ot switching devices, other means controllable at a distant point for operating the other paii of said devices, an allotter cooperating in the control ot one switching device i'n each pair, and means controlled by said allotter for temporarily preventing the operation of the switching device the pair of which was the last to be started.

7. In combination, an electric signal, two actuating circuits therefor, a pair of switching devices for controlling each of said circuits, means controllable at a distant point for operating one pair of switching devices, other means controllable at a distant point foroperating the other pair ot said devices, an allotter having two operating positions, means vactuated upon the association of said one pair of switching devices with said Vmeans at a distant point for moving said allotter into the irst operating position, means actuated in response thereto for completing the operation ot said one pair of switching devices, automatic means tor releasing said last mentioned devices, means operable upon the association of the second pair of devices with said other means at a distant point for moving said allotter into its second operating position, means actuatedV in response thereto for completing the operation of said second pair of devices, and, means operative until the release of a switching device of said one pair is started for maintaining said allotter'in its first operating position.

8. In combination, a plurality of telephone lines, a plurality of senders, selectively operable means tor associating any one of said senders with any one of said lines, an electric signal, twoy actuating circuits therefor, a pair oi: switching devices for Vcontrolling each ot said circuits, said devices being adjustable under the control of any one ot said senders` a finder for each pair of switching devices arranged to seize any one of said lines, mechanism for successively preselecting said iinders for service, means operative upon the connection of a sender toV a line for operating a preselected finder to seize said line, means operative thereupon for actuating said mechanism to preselect another finder for service, an allotterhaving two operating positions, means actuated upon the' association o'f one pairvoi switching devices with a sender for moving said allotter in to the iirst operating position, means actuated in response thereto for completing the operation of said one pair of switching devices, automaticemeans for releasing said last mentioned devices, means operablefupon the association of the second pair of devices with a sender for movingV said allotter Y into its second operating position, means actuated in response thereto for completing 7 the operation of said second pair of devices, and means operative until the release of a switching device of said one pair is'started for maintaining said allotter in its litirst operating position.

. 9. In combination, a signal, a plurality of switches arranged to actuate the same, an allotter having a plurality of positionsand controlling in its various positions the operationof said switches, means controlled by any one of said switches for moving said .allotter into a position permitting the operation of the controlling switch, and ,means operative thereupon for vpreventing the other switches from vactuating said allotter until said controlling switch successfully com-v pletes its operation. v

10. ln' combination, a signal, a plurality of selectively operable switching devices each arranged to control said signal, separate'means controllable at a distant point for operatingsaid devices, a sequence switch for each of said devices arranged to cooperate in their control, an allotter having a vplurality of operating positions, means 10o under the joint control of any one of said sequence switches andsaid allotter Afor causing one of said devices to actuate said signal, and means controlled by said actuated device for preventing the mentioned coperation of another of said sequence switches and said allotter. Y

11. In combination, a signal, two switches each arranged to actuate said signal, an allotter having a plurality of positions, means controlled by vthe rst switch for moving said allotter into a certainposition, means operative thereupon for actuating said first switch to actuate said si nal, means controlled by the second switch 'or-moving 115 the allotter into another position, means operative thereupon for causing said second switch to operate said signal, and means for preventing said second switch from operating said allotter until said Vsignal has 12o been successfully actuated by said rst switch. Y Y

12. ln combination, a signal, a plurality of switches arranged to control vthe actuation of the same,-an allotter having a plurality of positions and controlling in its various positions the operation ofV said switches, a circuit for said allotter having a common portion and a plurality of branches, a contact in each of said branches, each contact being operable by another one of said switches, means operable upon the actuation of any one of said contacts for moving said allotter into a position permitting the successful operation of the switch actuating the contact, a relay controlling the common portion of said circuit, and means for actuating said relay while a switch is successfully operated.

13. In combination, a signal, a plurality of selectively operable switching devices each arranged to control said signal, a plurality of senders, means for associating any one of said senders with any one of said switching devices, a sequence switch for each of said switching devices, an allotter having a plurality of operating positions, a circuit for said allotter having a normally closed common portion and one branch for each of the sequence switches, a normally open sequence switch Contact in each of said branches, means operable upon the successful adjustment of a selectively operable switching device Vfor operating the associated sequence switch to actuate its normally open contact, means operative thereupon for moving said allotter into a certain operating position, means operative in said position of the allotter for permitting the successful operation of the adjusted switching device, a relay controlling the common portion of said circuit, and a circuit for said relay jointly controlled by any one of said sequence switches and any one of said signals.

In witness whereof I hereunto subscribe my7name this 31st day of October, A. D. 191

FRANK N. REEVES. 

